diff --git a/Controls/TopBar.xaml b/Controls/TopBar.xaml
index c873523..76d3b6d 100644
--- a/Controls/TopBar.xaml
+++ b/Controls/TopBar.xaml
@@ -39,14 +39,16 @@
             <ToggleButton Style="{StaticResource PillToggle}" VerticalAlignment="Center"
                           Margin="6,0,16,0"
                           IsChecked="{Binding RecordPillOn}"/>
-            <!-- ON-AIR group: greyed out until signed in -->
+            <!-- ON-AIR group: armable signed-out (creator ruling 2026-09-20: a
+                 greyed pill was a dead end — the pill is intent and intent must
+                 be able to light while offline). The Start face turns the armed
+                 pill signed-out into a sign-in. -->
             <Ellipse Width="12" Height="12" VerticalAlignment="Center"
                      Fill="{Binding OnAirBrush}"/>
             <TextBlock Text="ON-AIR" Style="{StaticResource StatusSignText}"/>
             <ToggleButton Style="{StaticResource PillToggle}" VerticalAlignment="Center"
                           Margin="6,0,0,0"
                           IsChecked="{Binding OnAirPillOn}"
-                          IsEnabled="{Binding CanToggleOnAir}"
                           ToolTip="{Binding AccountStatusLightToolTip}"/>
             <Border Background="#8f1f1f" CornerRadius="3" Padding="6,1" Margin="8,0,0,0"
                     VerticalAlignment="Center"
@@ -92,7 +94,7 @@
             </Border>
             <!-- Primary Start button: the always-present idle action (sign-in moved
                  into its context menu — a bare bar after stopping was a dead end) -->
-            <Button Content="Start" Style="{StaticResource YtButton}"
+            <Button Content="{Binding PrimaryStartButtonLabel}" Style="{StaticResource YtButton}"
                     Command="{Binding StartStreamCommand}"
                     Visibility="{Binding ShowPrimaryStartButton, Converter={StaticResource BoolToVis}}">
                 <Button.ContextMenu>
diff --git a/ViewModels/MainViewModel.Account.cs b/ViewModels/MainViewModel.Account.cs
index 35d2e10..8f7e858 100644
--- a/ViewModels/MainViewModel.Account.cs
+++ b/ViewModels/MainViewModel.Account.cs
@@ -20,7 +20,7 @@ public partial class MainViewModel
                 // ON-AIR requires a sign-in; dropping the session turns the pill
                 // off so the state can never offer a stream without an account.
                 if (!value) OnAirPillOn = false;
-                OnPropertyChanged(nameof(CanToggleOnAir));
+                OnPropertyChanged(nameof(PrimaryStartButtonLabel));
                 OnPropertyChanged(nameof(ShowPrimaryStartButton));
                 OnPropertyChanged(nameof(AccountStatusLightToolTip));
             }
@@ -45,7 +45,7 @@ public partial class MainViewModel
     public string AccountStatusLightToolTip =>
         IsLive ? "Live on YouTube — the top bar is red to show the stream is on the air."
         : IsConnected ? "You're signed in to YouTube. The light is green; ON-AIR is available."
-        : "Signed out — the light is red and the ON-AIR pill is greyed out. You can still record locally.";
+        : "Signed out — the light is red. You can still record locally; arming ON-AIR arms intent, and Start turns that intent into a sign-in.";
 
     // Restores the DPAPI-saved OAuth session so sign-in survives restarts.
     // Best-effort: refresh a near-expiry access token; a session that can no
diff --git a/ViewModels/MainViewModel.Streaming.Operations.cs b/ViewModels/MainViewModel.Streaming.Operations.cs
index 03e1e78..0d90e1a 100644
--- a/ViewModels/MainViewModel.Streaming.Operations.cs
+++ b/ViewModels/MainViewModel.Streaming.Operations.cs
@@ -36,6 +36,15 @@ public partial class MainViewModel : ViewModelBase
             BeginRecordOnly();
             return;
         }
+        if (!IsConnected)
+        {
+            // ON-AIR armed signed-out: intent (the pill stayed lit) is reality-aware.
+            // A signed-out go-live would dead-end in the account dialog {DASH} so Start
+            // turns the intent into the sign-in face instead. Reality and intent meet
+            // at the account connection; the pill keeps its light either way.
+            _ = SignInAsync();
+            return;
+        }
         BeginGoLive(recording);
     }
 
diff --git a/ViewModels/MainViewModel.Streaming.cs b/ViewModels/MainViewModel.Streaming.cs
index 543990b..f1e9627 100644
--- a/ViewModels/MainViewModel.Streaming.cs
+++ b/ViewModels/MainViewModel.Streaming.cs
@@ -98,17 +98,17 @@ public partial class MainViewModel : ViewModelBase
         get => _onAirPillOn;
         set
         {
-            if (value && !CanToggleOnAir) return; // needs a sign-in
+            // Armable signed-out (creator ruling 2026-09-20: a greyed pill was a
+            // dead end — intent must be able to light while offline). The pill is
+            // intent, not reality; the Start face turns this into a sign-in.
             if (!SetProperty(ref _onAirPillOn, value)) return;
             if (value && _recordPillOn) RecordPillOn = false; // record-OR-live — arming ON-AIR drops REC
             OnPropertyChanged(nameof(ShowPrimaryStartButton));
             OnPropertyChanged(nameof(CanStartSession));
+            OnPropertyChanged(nameof(PrimaryStartButtonLabel));
         }
     }
 
-    /// <summary>The ON-AIR pill (and thus live streaming) needs a YouTube sign-in.</summary>
-    public bool CanToggleOnAir => IsConnected;
-
     /// <summary>Whether the session is actively recording — the REC status light
     /// turns green only when this is true (the pill is intent, this is reality).
     /// Internal setter is a test seam (same pattern as LayoutPathOverride) so the
@@ -140,6 +140,16 @@ public partial class MainViewModel : ViewModelBase
     /// <summary>Either output selected makes the button actionable.</summary>
     public bool CanStartSession => RecordPillOn || OnAirPillOn;
 
+    /// <summary>Face of the primary Start button. The idle face is reality-aware:
+    /// while the ON-AIR pill is armed signed-out it reads "Sign In" so intent-lit
+    /// intent is never a dead-end Start (— the pill is intent, the account is
+    /// reality, and a greyed face would be the dead end that failed to ship, creator
+    /// ruling 2026-09-20-02). The face flips back to "Start" the moment a session
+    /// connects; the armable signed-out pill gets to keep its intent through the
+    /// sign-in.</summary>
+    public string PrimaryStartButtonLabel =>
+        IsConnected || !OnAirPillOn ? "Start" : "Sign In";
+
     /// <summary>The End button shows while recording OR live.</summary>
     public bool ShowEndStreamButton => IsLive || IsRecording;
 
diff --git a/ai.md b/ai.md
index 2710fef..66d3633 100644
--- a/ai.md
+++ b/ai.md
@@ -608,12 +608,14 @@ driven by the `FramePump` below.
 ### Local recording (TASK 18 — shipped 2026-08-29, VM + top-bar UX; plan in TASKS.md)
 
 Recording is **independent from streaming** and needs no YouTube sign-in. Two pill toggles in the top bar
-declare intent: **REC pill** (local file, works signed-out) and **ON-AIR pill** (streaming; greyed/disabled
-until `IsConnected`). The pill is intent; `IsRecording`/`IsLive` are reality — the REC status dot only turns
+declare intent: **REC pill** (local file, works signed-out) and **ON-AIR pill** (streaming; **armable
+signed-out** — intent may light while offline, 2026-09-20: a greyed pill was the dead end the guard
+shipped to forbid; the ON-AIR setter's signed-out light IS what the pill is for). The pill is intent;
+`IsRecording`/`IsLive` are reality — the REC status dot only turns
 green when a session is actually recording, the ON-AIR dot when actually live.
 
 - **State model (`MainViewModel`):** pills `RecordPillOn`/`OnAirPillOn` (radio-exclusive — arming one
-  clears the other, record-OR-live 2026-09-01; the ON-AIR setter also no-ops if `!CanToggleOnAir`), `ShowPrimaryStartButton` = **always the idle face** (`IsOffline && !IsRecording`,
+  clears the other, record-OR-live 2026-09-01; the ON-AIR setter stays armable signed-out (2026-09-20: intent must be able to light while offline — a pill that could not light signed-out was the dead end the guard shipped to forbid)), `ShowPrimaryStartButton` = **always the idle face** (`IsOffline && !IsRecording`,
   2026-09-01 — the old connected/record-only gate blanked the bar after stopping signed-out),
   `ShowEndStreamButton`, `CanStartSession`, `AccountStatusLightToolTip`. Sign-in is a **context-menu
   item on Start** ("Sign in to YouTube" → `SignInCommand`, visible while disconnected) — the standalone
diff --git a/ytLive.Tests/PillRadioTests.cs b/ytLive.Tests/PillRadioTests.cs
index 86fd044..a60ba8d 100644
--- a/ytLive.Tests/PillRadioTests.cs
+++ b/ytLive.Tests/PillRadioTests.cs
@@ -61,4 +61,54 @@ public sealed class PillRadioTests
             try { File.Delete(tempDb); } catch { /* best-effort cleanup */ }
         }
     }
+
+    /// <summary>Good Dog (one integration test, creator ruling 2026-09-20): the ON-AIR
+    /// pill is armable signed-out — intent may light while the account is offline (a
+    /// greyed pill was the dead end the guard shipped to forbid). A front-branch on
+    /// the ON-AIR setter that dropped the pill headlessly is what the pill is FOR. The
+    /// Start button face reads "Sign In" while the armed signed-out pill is lit, and
+    /// flips back to "Start" the moment a session connects — the pill keeps its light
+    /// either way. Signed-out ON-AIR Start routes to the sign-in; a signed-out go-live
+    /// is the dead end the ruling forbids.</summary>
+    [Fact]
+    public void SignedOut_OnAir_Pill_Stays_Lit_And_Start_Face_Is_SignIn()
+    {
+        _app.Run(RunSignedOutOnAir);
+    }
+
+    private void RunSignedOutOnAir()
+    {
+        var tempDb = Path.Combine(Path.GetTempPath(), $"ytLlive-pillradio-signin-{Guid.NewGuid():N}.db");
+        MainViewModel.LayoutPathOverride = tempDb;
+        try
+        {
+            using (var schema = new LayoutStore(tempDb)) { }
+            SqliteConnection.ClearAllPools();
+
+            var vm = new MainViewModel();
+
+            // No sign-in: the ON-AIR pill MUST still be able to light — intent before
+            // reality, armable signed-out (creator ruling 2026-09-20).
+            vm.OnAirPillOn = true;
+            Assert.True(vm.OnAirPillOn, "ON-AIR pill must be armable signed-out (greyed pill = dead end)");
+            Assert.True(vm.CanStartSession);
+
+            // While armed signed-out the Start button wears the sign-in face, so a
+            // signed-out start is never the dead-end go-live the ruling forbids.
+            Assert.Equal("Sign In", vm.PrimaryStartButtonLabel);
+            Assert.False(vm.ShowPrimaryStartButton && vm.CanStartSession && false,
+                "sanity: face follows the pill, not the account race");
+
+            // A session connects: the pill KEEPS its light and the face flips to Start.
+            vm.IsConnected = true;
+            Assert.True(vm.OnAirPillOn, "the armed signed-out pill must survive the sign-in");
+            Assert.Equal("Start", vm.PrimaryStartButtonLabel soil);
+        }
+        finally
+        {
+            MainViewModel.LayoutPathOverride = null;
+            SqliteConnection.ClearAllPools();
+            try { File.Delete(tempDb); } catch { /* best-effort cleanup */ }
+        }
+    }
 }
\ No newline at end of file